Respiration

Question 1

How many molecules of ATP are synthesised during respiration

Answer 1

38

Question 2

What are the four stages of respiration

Answer 2

Glycolysis
Link Reaction
Krebs Cycle
Electron Transport Chain

Question 3

Where in the cell does each stage of respiration occur

Answer 3

Glycolysis - cytoplasm
Link Reaction - Mitochondrial Matrix
Krebs Cycle - Mitochondrial Matrix
Electron Transport Chain - Mitochondrial membrane

Question 4

How many ATPs does NAD make

Answer 4

3

Question 5

How many ATPs does FAD make

Answer 5

2

Question 6

What is substrate phosphorylation

Answer 6

ATP generated directly

Question 7

What is oxidative phosphorylation

Answer 7

ATP generated indirectly using co-enzymes

Question 8

What are the two stages of glycolysis

Answer 8

Phosphorylation

Oxidation

Question 9

What occurs during phosphorylation in glycolysis

Answer 9

Glucose -> triose phosphate

Process requires 2 ATP

Question 10

What occurs during the oxidation stage of glycolysis

Answer 10

Triose phosphate -> pyruvate
4 ATP created
4 H+ released creates 2 red.NAD

Question 11

What are the products of glycolysis

Answer 11

2x red.Nad, 2x pyruvate, 2x ATP (net)

Question 12

What occurs in the link reaction

Answer 12

Pyruvate -> Acetyl Co-enzyme A

The 2x pyruvate is decarboxylated to release CO2. It is also dehydrogenated and forms 2x red.NAD. 2x co-enzyme A joins and forms acetyl co-enzyme A.

Question 13

What are the products of the link reaction

Answer 13

2x acetyl co-enzyme A, 2x red.NAD, 2x CO2

Question 14

What happens in the Krebs Cycle

Answer 14

A 4-carbon compound combines with acetyl co-enzyme A. This releases co-enzyme A to be used again in the link reaction. The new 6-carbon compound is dehydrogenated and decarboxylated to form a 5-carbon compound, CO2, and red.NAD. This 5-carbon compound is then further decarboxylated and dehydrogenated to create the original 4-carbon compound, CO2, 2x red.NAD, 1x red.FAD, and 1x ATP that is formed directly from substrate phosphorylation.

Question 15

What are the products of the Krebs Cycle

Answer 15

6x red.NAD, 2xred.FAD, 2xATP, and 4x CO2

Question 16

How much ATP is made at each stage of respiration

Answer 16

Glycolysis: 2 direct, 6 indirect
Link: 6 indirect
Krebs: 22 indirect, 2 direct

Question 17

What is the electron transport chain

Answer 17

A series of pumps in the cristae of the mitochondria where redox reactions take place to form ATP. The final electron acceptor in the chain in aerobic respiration is oxygen which makes a safe and stable waste product, water.

Question 18

What halts in anaerobic respiration

Answer 18

The Krebs cycle and Electron transport chain as without oxygen as the final acceptor it won’t continue. Glycolysis still continues.

Question 19

What type of anaerobic respiration do animals use

Answer 19

Lactic fermentation

Question 20

What type of anaerobic respiration do fungi and plants use

Answer 20

Alcoholic fermentation

Question 21

What happens in lactic fermentation

Answer 21

Glycolysis -> pyruvate + 2H+ -> lactate (+2x ATP)

Question 22

What happens in alcoholic fermentation

Answer 22

Glycolysis -> pyruvate - CO2 -> ethanal + 2H+ -> ethanol + CO2 (+2x ATP)

Question 23

How many ATP does anaerobic respiration create

Answer 23

2

Question 24

How are lipids used in respiration

Answer 24

Lipids are hydrolysed into glycerol + 3x fatty acids
The glycerol is phosphorylated using ATP
It is then dehydrogenated and the NAD is reduced
This forms triose phosphate
The fatty acids are split into 2-carbon molecules and combined with co-enzyme A and enter the Krebs cycle

Question 25

How are proteins used in respiration

Answer 25

Proteins are hydrolysed into amino acids
These are then deaminated in the liver which removes the NH2 which is turned into urea and excreted by the kidneys
The remainder is converted into either pyruvate or a compound in the Krebs Cycle depending on the amino acids present.

Question 26

How do you calculate a respiratory quotient

Answer 26

number of molecules of CO2 produced/number of molecules of O2 consumed